当用户输入密码时，我不得不用星号替换点，因此我创建了自定义PasswordTransformationMethod：
public class LockerPasswordTransformationMethod extends PasswordTransformationMethod {
@Override
public CharSequence getTransformation(CharSequence source, View view) {
return new PasswordCharSequence(source);
}
private class PasswordCharSequence implements CharSequence {
private CharSequence mSource;
public PasswordCharSequence(CharSequence source) {
mSource = source;
}
public char charAt(int index) {
return '*';
}
public int length() {
return mSource.length();
}
public CharSequence subSequence(int start, int end) {
return mSource.subSequence(start, end);
}
}
}
我的xml：
<EditText
android:id="@+id/indicator"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:inputType="textPassword"
android:letterSpacing="1.2"
/>
用法：
mIndicator.setTransformationMethod(new LockerPasswordTransformationMethod());
不幸的是，它会立即将我的文本转换为星号，但我想在短时间内显示最后一个字符（就像inputType设置为password时的普通EditText一样），然后将其转换为星号。如何实现？
答案 0 :(得分：1)
您可以使用此自定义类。我对原始类进行了两处更改
点数值从＆＃39; \ u2022＆＃39;到＆＃39; \ u002A＆＃39; 然后替换此代码
int pref = TextKeyListener.getInstance().getPrefs(v.getContext());
if ((pref & SHOW_PASSWORD) != 0) {
if (count > 0) {
removeVisibleSpans(sp);
if (count == 1) {
sp.setSpan(new Visible(sp, this), start, start + count,
Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
}
}
}
与
removeVisibleSpans(sp);
sp.setSpan(new Visible(sp, this), start, start + count,
Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
这是customclass
import android.graphics.Rect;
import android.os.Handler;
import android.os.SystemClock;
import android.text.Editable;
import android.text.GetChars;
import android.text.NoCopySpan;
import android.text.Spannable;
import android.text.Spanned;
import android.text.TextUtils;
import android.text.TextWatcher;
import android.text.method.TransformationMethod;
import android.text.style.UpdateLayout;
import android.view.View;
import java.lang.ref.WeakReference;
public class CustomPasswordTransformationMethod
implements TransformationMethod, TextWatcher {
/* package */ static final Object ACTIVE = new NoCopySpan.Concrete();
/* package */ static final Object CAPPED = new NoCopySpan.Concrete();
/* package */ static final int SHOW_PASSWORD = 8;
private static CustomPasswordTransformationMethod sInstance;
private static char DOT = '\u002A';
public static CustomPasswordTransformationMethod getInstance() {
if (sInstance != null)
return sInstance;
sInstance = new CustomPasswordTransformationMethod();
return sInstance;
}
private static void removeVisibleSpans(Spannable sp) {
Visible[] old = sp.getSpans(0, sp.length(), Visible.class);
for (int i = 0; i < old.length; i++) {
sp.removeSpan(old[i]);
}
}
public CharSequence getTransformation(CharSequence source, View view) {
if (source instanceof Spannable) {
Spannable sp = (Spannable) source;
/*
* Remove any references to other views that may still be
* attached. This will happen when you flip the screen
* while a password field is showing; there will still
* be references to the old EditText in the text.
*/
ViewReference[] vr = sp.getSpans(0, sp.length(),
ViewReference.class);
for (int i = 0; i < vr.length; i++) {
sp.removeSpan(vr[i]);
}
removeVisibleSpans(sp);
sp.setSpan(new ViewReference(view), 0, 0,
Spannable.SPAN_POINT_POINT);
}
return new PasswordCharSequence(source);
}
public void beforeTextChanged(CharSequence s, int start,
int count, int after) {
// This callback isn't used.
}
public void onTextChanged(CharSequence s, int start,
int before, int count) {
if (s instanceof Spannable) {
Spannable sp = (Spannable) s;
ViewReference[] vr = sp.getSpans(0, s.length(),
ViewReference.class);
if (vr.length == 0) {
return;
}
/*
* There should generally only be one ViewReference in the text,
* but make sure to look through all of them if necessary in case
* something strange is going on. (We might still end up with
* multiple ViewReferences if someone moves text from one password
* field to another.)
*/
View v = null;
for (int i = 0; v == null && i < vr.length; i++) {
v = vr[i].get();
}
if (v == null) {
return;
}
removeVisibleSpans(sp);
LogUtil.d("data", "start" + start + " count" + count);
sp.setSpan(new Visible(sp, this), start, start + count,
Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
/* int pref = TextKeyListener.getInstance().getPrefs(v.getContext());
if ((pref & SHOW_PASSWORD) != 0) {
if (count > 0) {
removeVisibleSpans(sp);
if (count == 1) {
sp.setSpan(new Visible(sp, this), start, start + count,
Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
}
}
}*/
}
}
public void afterTextChanged(Editable s) {
// This callback isn't used.
}
public void onFocusChanged(View view, CharSequence sourceText,
boolean focused, int direction,
Rect previouslyFocusedRect) {
if (!focused) {
if (sourceText instanceof Spannable) {
Spannable sp = (Spannable) sourceText;
removeVisibleSpans(sp);
}
}
}
private static class PasswordCharSequence
implements CharSequence, GetChars {
private CharSequence mSource;
public PasswordCharSequence(CharSequence source) {
mSource = source;
}
public int length() {
return mSource.length();
}
public char charAt(int i) {
if (mSource instanceof Spanned) {
Spanned sp = (Spanned) mSource;
int st = sp.getSpanStart(ACTIVE);
int en = sp.getSpanEnd(ACTIVE);
if (i >= st && i < en) {
return mSource.charAt(i);
}
Visible[] visible = sp.getSpans(0, sp.length(), Visible.class);
for (int a = 0; a < visible.length; a++) {
if (sp.getSpanStart(visible[a].mTransformer) >= 0) {
st = sp.getSpanStart(visible[a]);
en = sp.getSpanEnd(visible[a]);
if (i >= st && i < en) {
return mSource.charAt(i);
}
}
}
}
return DOT;
}
public CharSequence subSequence(int start, int end) {
char[] buf = new char[end - start];
getChars(start, end, buf, 0);
return new String(buf);
}
public String toString() {
return subSequence(0, length()).toString();
}
public void getChars(int start, int end, char[] dest, int off) {
TextUtils.getChars(mSource, start, end, dest, off);
int st = -1, en = -1;
int nvisible = 0;
int[] starts = null, ends = null;
if (mSource instanceof Spanned) {
Spanned sp = (Spanned) mSource;
st = sp.getSpanStart(ACTIVE);
en = sp.getSpanEnd(ACTIVE);
Visible[] visible = sp.getSpans(0, sp.length(), Visible.class);
nvisible = visible.length;
starts = new int[nvisible];
ends = new int[nvisible];
for (int i = 0; i < nvisible; i++) {
if (sp.getSpanStart(visible[i].mTransformer) >= 0) {
starts[i] = sp.getSpanStart(visible[i]);
ends[i] = sp.getSpanEnd(visible[i]);
}
}
}
for (int i = start; i < end; i++) {
if (!(i >= st && i < en)) {
boolean visible = false;
for (int a = 0; a < nvisible; a++) {
if (i >= starts[a] && i < ends[a]) {
visible = true;
break;
}
}
if (!visible) {
dest[i - start + off] = DOT;
}
}
}
}
}
private static class Visible
extends Handler
implements UpdateLayout, Runnable {
private Spannable mText;
private CustomPasswordTransformationMethod mTransformer;
public Visible(Spannable sp, CustomPasswordTransformationMethod ptm) {
mText = sp;
mTransformer = ptm;
postAtTime(this, SystemClock.uptimeMillis() + 1000);
}
public void run() {
mText.removeSpan(this);
}
}
/**
* Used to stash a reference back to the View in the Editable so we
* can use it to check the settings.
*/
private static class ViewReference extends WeakReference<View>
implements NoCopySpan {
public ViewReference(View v) {
super(v);
}
}
}
答案 1 :(得分：0)
在您的on create方法中，请初始化editext。然后创建一个自定义类来执行此操作
EditText UPL =(EditText) findViewById(R.id.UserPasswordToLogin) ;
UPL.setTransformationMethod(new AsteriskPasswordTransformationMethod());
然后创建一个新的java类AsteriskPasswordTransformationMethod
public class AsteriskPasswordTransformationMethod extends PasswordTransformationMethod {
@Override
public CharSequence getTransformation(CharSequence source, View view) {
return new PasswordCharSequence(source);
}
private class PasswordCharSequence implements CharSequence {
private CharSequence mSource;
public PasswordCharSequence(CharSequence source) {
mSource = source; // Store char sequence
}
public char charAt(int index) {
return '*'; // This is the important part
}
public int length() {
return mSource.length(); // Return default
}
public CharSequence subSequence(int start, int end) {
return mSource.subSequence(start, end); // Return default
}
}
};